I meant Protein Digestive Aid by Nature's Sunshine. :)
Stomach acid lowers with age. At least 8 nutrients are dependant on adequate stomach acid: calcium, B9 and B12, magnesium, zinc, iron, vitamin C and beta carotene. There is betaine HCL with pepsin supplements to help increase stomach acid. My mother uses protein digestive aid from Nature's Own for her severely low stomach acid.
As the vitamin B12 levels slowly but surely decrease, neurological systems start to show up. Some people experience numbness or a crawling sensation rather than tingling. Vitamin B12 reference ranges are far too low in Australia and can miss a deficiency state.
If you decide you want to check your vitamin B12 levels out, then note that in Europe deficiency is classed as 550pg/mL (405.9 pmol/L) and under. This is still too low so aim for higher in the range. Recommended to try sublingual (under the tongue) B12 to see if you notice any improvement. I personally prefer the spray form but you can find this in tablets that dissolve under the tongue.